This invention relates generally to the packaging of sheet material in interfolded fashion, and more particularly concerns the configuration of interfolded multi-panel bundles or clips of sheet material which clips are more easily separated from each other during packaging.
Disposable products for home, health care, and industry, such as facial tissues, toilet tissue, industrial wipes, and the like, are frequently distributed to consumers in packages or boxes in which the sheet material is configured in interfolded multi-panel bundles or clips. A common example is the well known Kleenex facial tissue manufactured by Kimberly-Clark Corporation, the assignee of the present invention. As one Kleenex tissue is pulled from the box, it pulls the next tissue from the box so that each tissue "pops out" one at a time and is readily accessible for grasping and retrieval.
During the manufacturing and packaging process for interfolded multi-panel clips of sheet material, the interfolded clip of sheet material is formed by laying two webs of sheet material together. The webs are divided into sheets by lines of perforation. When the webs are laid together, the lines of perforation are staggered between the two webs so that the perforation on one web corresponds with the middle of the sheet of the other web and vice versa. The two webs are then folded accordian-style to create the panels, the sheet material between the fold lines. The clip includes a predetermined number of the interfolded sheets which go into a single box or dispenser.
Once the sheets have been interfolded into panels, it is necessary to separate the last two sheets on one clip from the first two sheets on the next clip in order to separate the clips for packaging in individual boxes or dispensers. Because the lines of perforation between the two webs are staggered one-half the length of each sheet, a loose tail equal to one-half the length of sheet results at the end of one clip and a similar loose tail exists at the beginning of the adjacent clip. These tails must be gathered up and refolded into accordian-fashion before the clips can be placed into boxes or dispensers.
In the case of industrial wipes where polymeric materials are frequently used, such polymeric materials have virtually no fold memory and as a result when clips of such materials are separated, the tails possess virtually no fold lines on which the operator can refold the tails into the resulting clips. In addition to the lack of fold memory, there may also exist air currents and drafts in the vicinity of the clip separation which further exacerbates the problem of refolding the tails into the separated clips. The unmanageable tails of the clips virtually eliminate the ability to use automatic separation and handling equipment in connection with the production of such interfolded multi-panel clips made of polymeric material.